Detent for locking knob of a privacy lock

ABSTRACT

A door latch, the knobs of which may be turned either clockwise or counterclockwise for operating the latch bolt is described. One of the knobs engages the corresponding escutcheon when the knob is pushed towards the door to prevent rotation and provide a privacy lock. Translation of the locking knob is inhibited by an elastic detent in the form of bendable fingers on the knob escutcheon engaged by a bullet-shaped member on the knob. The door latch is made of injection molded plastic and the two escutcheons are held together by a single axial screw.

United States Patent [191 Ramsey [451 July 30, 1974 I DETENT FOR LOCKING KNOB OF A PRIVACY LOCK [75] Inventor: Joe E. Ramsey, Walnut, Calif.

[73] Assignee: Acme General Corporation,

Monrovia, Calif.

22 Filed: Oct. 24, 1973 211 App]. No.: 409,236

52 us. Cl. 292/359, 292/1310. 38 [51] Int. Cl E05b 13/00 [58] Field of Search 292/336.3, 347, 357, 359, 292/D1G. 38

[56] References Cited UNITED STATES PATENTS 1,522,628 1/1925 Holt 292/359 2,295,435 9/1942 Tcich 292/359 3,580,622 5/1971 Morgan 292/359 X FOREIGN PATENTS OR APPLICATIONS 666,937 2/1952 Great Britain 292/3363 Primary Examiner-Robert L. Wolfe Assistant ExaminerRichard P. Tremblay Attorney, Agent, or FirmChristie, Parker & Hale 5 7] ABSTRACT A door latch, the knobs of which may be turned either clockwise or counterclockwise for-operating the latch bolt is described. One of the knobs engages the corresponding escutcheon when the knob is pushed towards the door to prevent rotation and provide a privacy lock. Translation of the locking knob is inhibited by an elastic detent in the form of bendable fingers on the knob escutcheon engaged by a bullet-shaped member on the knob. The door latch is made of injection molded plastic and the two escutcheons are held together by a single axial screw.

4 Claims, 5 Drawing Figures PMENIEB swmuf a NWNK SHEET 2 BF 3 l I 35 M 20 F/EE DETENT FOR LOCKING KNOB OF A PRIVACY LOCK CROSS REFERENCE TO RELATED APPLICATIONS This is a division of application Ser. No. 261,516, filed June 9, I972 now U.S. Pat. No. 3,792,886.

BACKGROUND U.S. Pat. No. 3,580,622 describes an injection molded plastic privacy lock or door latch where two substantially identical escutcheons are interconnected by a single axial screw. One of the knobs in that door latch may be shifted axially to engage the corresponding escutcheon to provide a privacy lock. Axial translation of the locking knob was inhibited by an elastic detent in the form of a finger on the knob engaging a peripheral region of the mounting escutcheon.

BRIEF SUMMARY OF THE INVENTION Thus, in practice of this invention according to a presently preferred embodiment, there is provided a two-way door latch having first and second escutcheons insertable into an opening through a door and defining a knob axis. A knob is mounted on each escutcheon for rotation about the knob axis. One of the knobs may be translatable along the knob axis for engaging its respective escutcheon for forming a privacy lock. A pair of opposed fingers on one of the escutcheons engage the locking knob to form a detent.

DRAWINGS These and other features and advantages of the present invention will be appreciated as the same becomes better understood by reference to the following detailed description of a presently preferred embodiment when considered in connection with the accompanying drawings wherein:

FIG. 1 illustrates in partial longitudinal cross section a pair of interlocking escutcheons and a locking knob in a door latch constructed according to principles of this invention;

FIG. 2 is a longitudinal cross section through the locking escutcheon and transverse to the cross section of FIG. 1;

FIG. 3 is an end view of the locking escutcheon;

FIG. 4 is a fragmentary transverse cross section of the locking escutcheon;

FIG. 5 is a transverse cross section of the locking knob.

DESCRIPTION FIG. 1 illustrates in longitudinal cross section a door latch constructed according to principles of this invention. Three principal elements of the door latch are illustrated in this cutaway view. A locking escutcheon has a peripheral flange 21 abutting one face of a door 22 shown only in phantom. The locking escutcheon 20 has a cylindrical skirt 26 that fits into an opening 27 through the door. A free escutcheon 23 is partially exploded from the other face of the door in this view and when fully installed, its flange 24 abuts the opposite face of the door from the locking escutcheon. The escutcheon used in a privacy lock on the locking side of the door (e.g., inside a bathroom) is referred to as the locking escutcheon. The opposite one is referred to as the free escutcheon. Both flanges 21 and 24 may have radiating reinforcing ribs 25 on their inner sides for maximum strength.

The locking escutcheon has a pair of sockets 28 into which posts 29 slide for aligning the two escutcheons. Preferably, the two posts and sockets are made in sets of dissimilar sizes to assure proper assembly of the two escutcheons. The sockets and posts are relatively long so that the two escutcheons may stay in engagement over quite a distance. Thus, the door latch assembly may be used on doors having a variety of thicknesses, such as, for example, from about I A to 1 13/16 inch. The locking escutcheon engages the door by its flange 21 and the skirt 28. The free escutcheon engages the door by its flange 24 and is positioned by the locking escutcheon. The two escutcheons when engaged in this manner define a knob axis extending normal to the faces of the door.

The two escutcheons are fastened together by a screw (not shown) which passes through a hole 31 on th knob axis of the free escutcheon 23. Small flats in the hole 32 lightly hold the screw in the hole prior to installation of the door latch. When assembled, the threaded portion of the screw goes into a hole 33 on the axis of the locking escutcheon 20. This hole 33 has a smaller diameter than the screw threads so that the threads cut into the plastic and secure the escutcheons together.

Knobs are mounted on the escutcheons for limited rotation about the knob axis. A locking knob 38 is mounted on the locking escutcheon 20. The free knob (not shown) mounted on the free escutcheon 23 is generally similar to the locking knob 38 except for absence of means for engaging the free escutcheon for the locking function. The free knob is retained on the free escutcheon in the same manner as the locking knob is retained on the locking escutcheon. Each knob has a shaft 39 that fits into the hub 41 of the escutcheon. The shaft has a short ramp 42 that rides over a corresponding ramp 43 inside the hub of the escutcheon (FIG. 4). To assemble the knob onto the escutcheon, the two are forcibly pressed together with the ramps in alignment. This causes a slight elastic deformation of the shaft and hub and permits the knob to enter. Thereafter, the knob is retained in place as the shoulder at the end of the knob ramp engages a shoulder 44 within the escutcheon. A raised portion 45 within the escutcheon engages the sides of the ramp 42 on the shaft and thereby acts as a stop limiting the extent of rotation of the knob.

The locking knob has a pair of sockets 46 in which pins 47 are seated (one of the pins is deleted in FIG. I). The free knob (not shown) has sleeves corresponding to the sockets 46 through which the pins 47 extend. The pins are free to slide longitudinally through the sleeves in the free knob for accommodating different door thicknesses. The pins extending between the two knobs assure that they rotate together about the knob axis. The sleeves are long enough to engage a long part of the pins and assure that there is minimal twisting of the knobs relative to each other. The gripping body of the knob is open on its outer end and may be closed with a snap-in decorative cap 48. When used as privacy lock, the cap on the free knob may have a central aperture for actuating an external release mechanism in the same general manner as described in U.S. Pat. No. 3,580,622.

ing through the axial hole. About midway along the.

length of each of the fingers there is an outer ridge 53 which can engage an inwardly extending annular ridge 54 within the shaft 39 of the knob. The opposed ridges 53 and 54 on the fingers and knob, respectively, cooperate to act as a detent for yieldably retaining the knob in either of two axial positions. As illustrated in FIG. 1, 1

the locking knob 38 is axially displaced away from the door 23 in its unlocked position. To lock the doorlatch, the knob is pressed inwardly to a position as shown in phantom in FIG. 1. This causes the ridge 54 in the knob shaftto over-ride the ridges 53 on the fingers thereby elastically bending the fingers inwardly and yieldably retaining the knob in either. its locked or unlockedposition.

A bullet-shaped plug 56 (see also FIG. fits between the free ends of the fingers 52, remote from the enlarged central portion 51 for providing inward lateral support of the free ends of the fingers and preventing them from collapsing too readily as the detent overrides. Thus, instead of merely being cantilevered outwardly from the enlarged portion, the fingers are also supported by the plug at the free end. The plug 56 is mounted in the locking knob by a transverse web 57. It will be noted that such a plug and web are absent in the free knob to permit access by a screw driver to the screw for holding the escutcheons together.

The locking knob and locking escutcheon can beengaged by complementary crenellations for preventing rotation. The locking escutcheon has a series of internal notches or crenels 58 inside the end of the hub (FIGS. 3 and 4). The locking knob has an annular groove 59 between the shaft 39 and the gripping portion of the knob (FIGS; 1 and 5). A plurality of teeth or merlons 61 extend into the groove and are complementary to the notches 58 in the hub of the escutcheon.

When the knob is pressed towards the door in its locking position, the teeth 61 engage the notches 58 and prevent the knob from being rotated.

In addition, the locking knob has a pair of notches complementary to the web 49 (FIG. 3) within the locking escutcheon. This also serves to prevent the knob from rotating. Since the notches at the inner end of the shaft and the teeth 61 near the outer end of the shaft are axially spaced on the knob, any tendency for skewing of the knob which could cam it out of its locking position is prevented. It will be apparent that either the teeth 61 or notches may be employed on the locking knob for engaging it with the escutcheon and preventing knob rotation.

The locking engagement of the locking knob and escutcheon is employed when a privacy lock is desired, such as, for example, on a bathroom door. In many applications, a passage lock is desired and identical parts may be used with the sole exception that an additional ring or extension 63 (FIG. 4) is made integral with the outer end of the hub on the locking escutcheon. This added ring of material extends to the root of the groove 4 59 in the knob and prevents the locking knob from being translated, thereby preventinglocking;

Many additional details of the two way door latch are described and illustrated in the above-identified parent application. These features are not required for an understanding of the present invention. Although but one embodiment of detent for a translatable locking knob has been shown and described in detail herein, many modifications and variations will be apparent to one skilled in the art. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a door latch having a locking knob selectively interlockable with a corresponding escutcheon member for preventing rotation of the knob about the knob axis upon translation of the locking knob along the knob axis, and wherein the the latch is fastened together by a single axial screw, an improved detent for inhibiting translation of the locking knob along the knob axis comprising:

a pair of opposed fingers partially surrounding the axial screw and cantilevered from the escutcheon towards the locking knob;

means connected to the locking knob on the knob axis and fittable between the fingers for outwardly directed support of the free ends thereof;

detent means on the outside of the fingers; and

means in the locking knob for engaging the detent means and elastically bending the fingers upon translation of the locking knob along the knob axis.

2. In a door latch as defined in claim 1, an improved detent wherein each finger is a portion of an annular cylinder, the detent means on the fingers comprises an annular ridge onthe outside of the fingers between the cantilevered end and the supported free end thereof; and the means forengaging comprises an inwardly directed'ridge engageable with the annular ridge.

3. In a door latch as defined in claim 2, an improved detent wherein the means fittable between the fingers comprises:

an axial bullet shaped member; and

a transverse web for supporting the bullet shaped member in the knob.

4. In a door latch to be mounted on a door having an opening therethrough adjacent one edge and having a hole in said edge into the opening, including two escutcheon members respectively insertable into and adapted to overlie the ends of the opening through the door and defining a knob axis, a single connecting means coaxial with the knob axis for interconnecting the escutcheon members, a pair of knobs respectively mounted on the escutcheon members for rotation about the knob axis, and means connected to the knobs for retracting the latch bolt, and wherein one of the knobs is a locking knob selectively interlockable with .the corresponding escutcheon member for preventing rotation of the knobs about the knob axis upon translation of the locking knob along the knob axis, an improved detent for inhibiting translation of the locking knob along the knob axis comprising:

a pair of opposed fingers partially surrounding the means for interconnecting and cantilevered from the respective escutcheon towards the locking knob;

6 means connected to the locking knob on the knob ported free end thereof; and

axis and fittable between the fingers for outwardly means in the locking knob for engaging the detent directed support of the free ends thereof; and elastically bending the fingers upon translation detent means on the outside of the fingers intermediof the locking knob along the knob axis.

ate between the cantilevered end and the sup- 5 Po-ww v UNITED STATES PATENT OFFICE 56 I CERTIFICATE OF CORRECTION Patent WM Dated ui 30, 1974 Inven.tot(s) JOE B.

It is certified that error appears in theabove-identified patent and that said Letters Patent are hereby corrected as shown below:

Front page, line 3,' "Joe E. Ramsey" should be ---Joe B. Ramsey--.

Signed and sealed this 19th day of November 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. In a door latch having a locking knob selectively interlockable with a corresponding escutcheon member for preventing rotation of the knob about the knob axis upon translation of the locking knob along the knob axis, and wherein the the latch is fastened together by a single axial screw, an improved detent for inhibiting translation of the locking knob along the knob axis comprising: a pair of opposed fingers partially surrounding the axial scrEw and cantilevered from the escutcheon towards the locking knob; means connected to the locking knob on the knob axis and fittable between the fingers for outwardly directed support of the free ends thereof; detent means on the outside of the fingers; and means in the locking knob for engaging the detent means and elastically bending the fingers upon translation of the locking knob along the knob axis.
 2. In a door latch as defined in claim 1, an improved detent wherein each finger is a portion of an annular cylinder, the detent means on the fingers comprises an annular ridge on the outside of the fingers between the cantilevered end and the supported free end thereof; and the means for engaging comprises an inwardly directed ridge engageable with the annular ridge.
 3. In a door latch as defined in claim 2, an improved detent wherein the means fittable between the fingers comprises: an axial bullet shaped member; and a transverse web for supporting the bullet shaped member in the knob.
 4. In a door latch to be mounted on a door having an opening therethrough adjacent one edge and having a hole in said edge into the opening, including two escutcheon members respectively insertable into and adapted to overlie the ends of the opening through the door and defining a knob axis, a single connecting means coaxial with the knob axis for interconnecting the escutcheon members, a pair of knobs respectively mounted on the escutcheon members for rotation about the knob axis, and means connected to the knobs for retracting the latch bolt, and wherein one of the knobs is a locking knob selectively interlockable with the corresponding escutcheon member for preventing rotation of the knobs about the knob axis upon translation of the locking knob along the knob axis, an improved detent for inhibiting translation of the locking knob along the knob axis comprising: a pair of opposed fingers partially surrounding the means for interconnecting and cantilevered from the respective escutcheon towards the locking knob; means connected to the locking knob on the knob axis and fittable between the fingers for outwardly directed support of the free ends thereof; detent means on the outside of the fingers intermediate between the cantilevered end and the supported free end thereof; and means in the locking knob for engaging the detent and elastically bending the fingers upon translation of the locking knob along the knob axis. 